The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp having a waterproof cover for sealing the opening in a lamp body into which a bulb socket is inserted.
A vehicular lamp having an aiming mechanism incorporated therein is generally constructed as shown in FIG. 11. As shown, a lens 102 is mounted on the front opening of a lamp body 101 to thereby form a lamp chamber 103. A reflector 104 is mounted within the lamp chamber 103 in such a manner as to be tiltable horizontally and vertically.
A bulb 106 is inserted into a bulb socket 105, which is removably attached to the reflector 104. For this purpose, a relatively large bulb insertion hole 107 is formed in the rear side of the lamp body 101. A bulb socket mounting portion 108 of the reflector and the bulb socket 105 (referred to as bulb socket components) are exposed to the exterior through the bulb insertion hole 107 so as to allow for electrical connection by means of a connector or the like. Unless the bulb insertion hole 107 is made larger in diameter than the bulb socket 105, when the reflector 104 is tilted for an aiming adjustment, the bulb socket components 105 would interfere with the lamp body 101. It is for this reason that the bulb insertion hole 107 is provided.
A waterproof cover 109 is fitted in the space between the bulb socket components 105 and the bulb insertion hole 107 for waterproofing purposes. As shown in FIG. 12(a), which shows a radial portion of the waterproof cover 109 in an enlarged form, the waterproof cover 109, which has the form of a ring-like plate made of a water-tight elastic material such as rubber, consists of an inner portion 110, a thick outer portion 111, and a middle portion 112, shaped wavy in cross section, connecting the inner portion 110 and the outer portion 111. The inner portion 110 closely contacts the circumferential outer surface. The outer portion 111 is fitted to a tubular wall 113 of the bulb insertion hole 107. The outer portion 111, which is applied to the tubular wall 113, closely contacts the tubular wall 113 due to the elasticity of the waterproof cover 109.
In order to obtain more reliable coupling of the tubular wall 113 with the outer portion 111, the coupling structure may be modified by providing a ring-like strip 113a around the circumferential outer surface of the tubular wall 113, while a ring-like groove 111a, which receives the raised strip 113a of the tubular wall 113, is formed in the inner surface of the outer portion 111.
In the conventional waterproof cover where the outer portion 111 of the waterproof cover 109 is applied to the outer side of the tubular wall 113 of the bulb insertion hole 107 of the lamp body 101, the elasticity of the waterproof cover 109 deforms the outer portion 111 outwardly in the radial direction. That is, after the outer portion 111 of the waterproof cover 109 is applied to the tubular wall 113, the elasticity of the waterproof cover deforms the outer portion 111 as shown in FIG. 12(b). In this deformed state, the contact area of the outer portion 111 against the outer surface of the tubular wall 113 is narrowed, so that the waterproofing ability is reduced between the outer portion 111 and the tubular wall 113.
To mount the waterproof cover 109, the outer portion 111 thereof must be expanded against the elastic force thereof so as to cover the tubular wall 113 of the bulb insertion hole 107. To expand the outer portion, a large force is required, thus making it difficult to apply the outer portion 111 to the tubular wall 113. If the elasticity of the waterproof cover 109 is increased to improve the contact of the outer portion 111 with the tubular wall 113 for the purpose of improving the waterproofing ability, a further increased force is required for expanding the outer portion 111. The work required to apply the waterproof cover 109 is also more difficult. In the case where the raised strip 113a is provided on the tubular wall 113, the outer portion 111 must be expanded beyond the raised strip 113a. Thus, the force required is further increased, resulting in more difficulty in mounting the waterproof cover.
As shown in FIG. 12(c), when the reflector 104 is tilted for performing an aiming adjustment after the waterproof cover 109 has been mounted on the bulb insertion hole 107, the bulb socket components 105 are tilted together with the tilting motion of the reflector 104. The middle portion 112 of the waterproof cover 109 is deformed in the direction of its thickness. In some cases, a part of the bulb socket components 105 may contact the waterproof cover 109. In the contacting state, the bulb socket components 105 can interfere with the reflector 104 during tilting motion. The operation for the aiming adjustment is thus hindered.